Grout containment sheet and method

ABSTRACT

A water-impermeable grout containment sheet and a method for using the sheet, for example, during the construction of a roadway to support vehicular traffic. An excavation is first cut into a road bed, and a moisture (i.e., water) impermeable grout containment sheet is laid inside the excavation. A plurality of concrete panels are positioned adjacent one another to be coupled together within the excavation, such that at least one of the panels sits on top of the water-impermeable grout containment sheet. Grout is then pumped below the one panel to hold the panel in place within the excavation. The water-impermeable grout containment sheet lies between the grout and the road bed to establish a containment envelope to stop the grout from migrating away from the panel and prevent water from seeping outwardly from the grout into the road bed and into the grout from the excavation.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a moisture (i.e., water) impermeable groutcontainment sheet and to a method including the step of locating thesheet within an excavation so as to lie between a (e.g., concrete) panelthat has been lowered into the excavation and grout that has been pumpedbelow the panel. The group containment sheet and method have particularapplication during roadway construction or repair where a plurality ofconcrete panels are laid in excavations formed in a road bed andconnected to one another to support vehicular traffic.

2. Background Art

As new communities are built, it is essential to have a roadway systemto link each community with neighboring communities. Therefore, a seriesof highways and freeways are constructed to support vehicular traffic. Acommon technique for building such roadways is to lay a number of heavyconcrete panels or slabs end-to-end and side-by-side one another. All ofthe panels must be held in place relative to one another and connectedtogether to establish a smooth and continuous driving surface. Theforegoing is often accomplished by first grading a road bed and cuttingexcavations therein within which the concrete panels are laid.

Once the concrete panels are located within the excavations, grout istypically pumped below the panels to retain the panels above the roadbed. However, with the heavy panels sitting on top, the grout has beenknown to migrate underneath adjacent panels located within a singleexcavation or within adjacent excavations. Such migration can adverselyaffect the stability and level of the concrete panel relative to otherpanels. Moreover, the water with which the grout is mixed can sometimesseep into and be absorbed by the road bed below the panel. What is evenmore, the grout lying below the panel within the excavation issusceptible to the negative effects of being exposed to too much water.Such additional water may originate as rain water and/or ground waterfrom the road bed. Until it is completely cured and hardened, whichcould take up to seven days or more, grout which becomes either too dryor too wet may become brittle or weakened and lose its maximumstructural integrity and load-bearing ability.

Therefore, what would be desirable is a means to prevent the grout thatis pumped between a concrete and and the road bed upon which the panelis laid from migrating away from the panel as well as losing itsmoisture and becoming too wet throughout the road construction project.

SUMMARY OF THE INVENTION

Briefly, and in general terms, a grout containment sheet and method aredisclosed having particular application, for example, during roadwayconstruction or repair when excavations are cut into a road bed and(e.g., precast concrete) panels are laid inside the excavations to beconnected end-to-end and/or side-by-side. Prior to laying a panel withinan excavation, a moisture (i.e., water) impermeable (e.g., polyurethane)grout containment sheet is positioned inside the excavation to cover atleast the bottom thereof. The grout containment, sheet must besufficiently strong to prevent water from passing therethrough.

The panel is lowered into the excavation so as to lie upon the groutcontainment sheet. In order to hold the panel in place within theexcavation, grout or a similar adhesive bonding material is pumped belowthe panel such as, for example, by way of filler tubes which run throughthe panel. Thus, the grout containment sheet lies between the grout andthe road bed above which the panel is located. By virtue of theforegoing, the grout containment sheet establishes a containmentenvelope around the grout throughout the construction project to preventthe grout from migrating away from the panel. At the same time, thegrout containment sheet creates a barrier that prevents the grout fromboth drying out as a consequence of the moisture of the grout beingabsorbed by the road bed and from becoming too wet as a consequence ofbeing exposed to rain water and ground water. Accordingly, the maximumstrength, structural integrity and load-bearing characteristics of thegrout upon which the panel is laid and supported can be maintained.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an excavation that has been cut into a road bed and a groutcontainment sheet located within and covering the bottom of theexcavation according to a preferred embodiment of this invention;

FIG. 2 shows a solid panel such as, for example, a precast concretepanel used during the construction of a roadway lowered into theexcavation and laying upon the grout containment sheet; and

FIG. 3 shows an adhesive bonding material (e.g., grout) pumped into theexcavation below the panel, such that the grout containment sheetcreates a water impermeable containment barrier between the grout andthe road bed.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Shown and described herein are a water-impermeable grout containmentsheet and a method for using the sheet with a solid (e.g., concrete)panel or slab where the panel is transported to and laid upon the sheetafter the sheet is first located inside an excavation that is cut into asolid surface. By way of example, the grout containment sheet and methodherein disclosed have particular application during roadway constructionand/or repair where a plurality of concrete panels are laid inside oneor more excavations so as to be connected end-to-end and/or side-by-sideone another. In this same regard, the system and method are alsoadvantageous to facilitating the removal of a panel from its excavationshould such removal be required during subsequent roadway maintenanceand repair.

Turning to the drawings, FIG. 1 shows a single excavation 10 that hasbeen cut into a road bed 15. The excavation 10 can be cut by means ofany of a variety of available construction machinery and plays no rolein the present invention. In the event a roadway is being constructed,either a single continuous excavation or a series of adjacentexcavations will be cut into the road bed for a purpose that will soonbe explained. The dimensions of the excavation 10 will depend upon thepurpose thereof.

In accordance with a preferred embodiment of this invention, a moisture(i.e., water) impermeable grout containment sheet 20 is laid inside theexcavation 10 so as to completely cover the bottom thereof. It isimportant that the grout containment sheet 20 be long enough toinitially extend upwardly and over top of the road bed 15 so that thesheet will not be pulled entirely inside the excavation 10 when a heavypanel is laid upon the sheet. The grout containment sheet 20 may becarried to the construction site, for example, on a roll of continuoussheet material which is cut to size. Depending upon the size of theexcavation 10, it may be necessary to add one or more additionalcontainment sheets (not shown) which overlap one another in end-to-endalignment. By way of example only, the water-impermeable groutcontainment sheet 20 has a thickness of at last 6 mils. The sheet 20which covers the bottom of the excavation 10 must be manufactured from amaterial (e.g., polyurethane) that is strong enough to support a load(e.g., a concrete panel) located inside the excavation 10 and preventwater from passing through the sheet.

With the grout containment sheet 20 laid inside the excavation 10 andcovering the bottom thereof, and referring now to FIG. 2 of thedrawings, a (e.g., precast) panel 25 that is manufactured from concreteor any other suitable durable and weather-resistant material istransported to and lowered, by means of an overhead crane, or the like,into the excavation. Thus, the panel 25 sits on the grout containmentsheet 20, and the sheet lies between the panel 25 and the solid surface(e.g., the road bed 15) into which the excavation has been cut. The endsof the grout containment sheet 20 may then be shortened (i.e., cut) soas to conform to the dimensions of the excavation 10 and the panel 25that has been lowered therewithin and laid upon the sheet.

FIG. 3 of the drawings shows a conventional bonding or adhesive fillermaterial 30, such as grout, or the like, being pumped below the panel 25within the excavation 10. The grout 30 may be pumped underneath thepanel 25 by way of one or more filler tubes 32 that run completelythrough the panel. For example, if the panel 25 is a precast concretepanel, the filler tubes (e.g., 32) are typically embedded within thepanel during the manufacturing (i.e., casting) process. The grout 30creates a bond to hold the panel 25 in place within the excavation.Moreover, the grout 30 also creates a platform below the panel 25,whereby the panel can be selectively raised or elevated within theexcavation 10 in order to be made level with adjacent panels (e.g.,designated 35) which are already in place within the excavation.

Accordingly, it may be appreciated that the water-impermeable groutcontainment sheet 20 lies between the grout 30 and the bottom of theexcavation 10 that has been cut into the solid surface (i.e., road bed15) to receive the (e.g., concrete) panel 25. By virtue of theforegoing, the containment sheet 20 establishes a liner or barrier toprevent the grout bonding material 30 from migrating away from the panel25 and flowing below an adjacent panel 35. To this end, portions of thesheet 20 are pulled upwardly to create a peripheral fold (designated 22in FIGS. 2 and 3) which surrounds the panel 25. Thus, the water which ismixed into the grout will not pass downwardly through the groutcontainment sheet 20 to be absorbed by and contaminate the ground aroundand below the excavation. In this same regard, and as another importantadvantage, the water-impermeable grout containment sheet 20 creates anenvelope around the panel 25 and the grout 30 below the panel 25 so asto prevent the grout from becoming saturated with rain or ground waterto which the grout may otherwise be exposed at the construction site.That is to say, grout is known to erode and become weaker as aconsequence of either losing water or being mixed with too much water.However, the grout containment sheet 20 maintains the structuralintegrity and load bearing characteristics of the grout during the timenecessary for the grout to be fully cured and hardened.

What is even still more, the grout containment shed 20 facilitates aremoval of the panel 25 from the excavation 10 for subsequent repair orreplacement. By spraying or coating the bottom of the panel 25 at thetime of construction with a conventional liquid bond breaker, the panelcan be titled out of the excavation 10 so as to be either replaced witha different panel or cleaned, repaired and returned to the excavation.In this case, the grout 30 will adhere to the grout containment sheet 20so as to permit a relatively easy separation of the panel 25 from thegrout 30 which remains inside the excavation.

As previously explained, a plurality of panels, like those designated 25and 35, which have been lowered into respective excavations or a singlecontinuous excavation, like that designated 10, can be connected, suchas by means of dowel bar couplers (designated 40 in FIG. 3), end-to-endand/or side-by-side. Thus, a continuous roadway may be constructed alonga road bed (e.g., 15) over which vehicular traffic can travel.

1. A method for installing at least a first panel on a surface, saidmethod comprising the steps of: placing a moisture-impermeable sheetover the surface; laying the first panel on top of themoisture-impermeable sheet; and pumping an adhesive bonding materialbetween the first panel and the moisture-impermeable sheet such thatsaid sheet lies between the adhesive bonding material and the surfaceover which the sheet is placed.
 2. The method recited in claim 1,comprising the additional step of cutting an excavation into a road bedsuch that said excavation forms the surface upon which saidmoisture-impermeable sheet is placed.
 3. The method recited in claim 2,comprising the additional step of positioning said moisture-impermeablesheet within the excavation so as to form a containment envelope aroundthe adhesive bonding material for preventing said bonding material frommigrating away from the first panel.
 4. The method recited in claim 2,comprising the additional step of manufacturing saidmoisture-impermeable sheet from a material that is impervious to thepassage of water therethrough so as to separate the adhesive bondingmaterial from the excavation.
 5. The method recited in claim 2,comprising the additional steps of laying a second panel within theexcavation adjacent said first panel; and coupling said first and secondpanels to one another to establish a roadway to support vehiculartraffic thereover.
 6. The method recited in claim 1, wherein saidadhesive bonding material is grout.
 7. The method recited in claim 1,comprising the additional step of manufacturing said first panel fromconcrete.
 8. A method for constructing a roadway to support vehiculartraffic thereover, said method comprising the steps of: cutting anexcavation into a road bed; placing a moisture-impermeable sheet insidethe excavation; laying a plurality of concrete panels adjacent oneanother within the excavation such that at least a first of saidconcrete panels sits on top of said moisture-impermeable sheet; pumpinggrout between the first concrete panel and the moisture-impermeablesheet such that said sheet creates a barrier between the grout and theexcavation for preventing the grout from migrating away from the firstconcrete panel within the excavation; and coupling said plurality ofadjacent concrete panels one to the other to establish said roadway.